Research into a portable DIY building-bridging system that connects ground spaces with interstices and rooftops. Pedestrians using rope ladders can traverse from sidewalk to roof with little effort, and find themselves interacting with a previously ignored building. “Building new layers in urban heights” is part of ongoing research by RoToR into the categories of “Terrae,” “Water,” and “Aire.” RoToR is a free network of collaborators who seek to create new situations. It was initiated in Barcelona in 2001 by Vahida Ramujkic and Laia Sadurní.